package openlibrary

import (
	"encoding/json"
	"io"
	"net/http"
	"net/url"
	"strconv"
	"strings"
)

type OpenLibraryQueryResult struct {
	Books    []OpenLibraryBook `json:"docs"`
	NumFound int               `json:"numFound"`
}

type OpenLibraryBook struct {
	Title         string   `json:"title"`
	Authors       []string `json:"author_name"`
	OpenLibraryId string   `json:"cover_edition_key"`
}

func CallOpenLibrary(searchterm string, limit int, offset int) (OpenLibraryQueryResult, error) {
	var queryResult OpenLibraryQueryResult
	baseUrl := "https://openlibrary.org"
	booksApiUrl := "search.json"
	u, err := url.Parse(baseUrl)
	if err != nil {
		return queryResult, err
	}
	u = u.JoinPath(booksApiUrl)
	if limit != 0 {
		addQueryParamInt(u, "limit", limit)
	}
	if offset != 0 {
		addQueryParamInt(u, "offset", offset)
	}
	addQueryParam(u, "q", searchterm)
	client := &http.Client{}
	req, err := http.NewRequest("GET", u.String(), nil)
	if err != nil {
		return queryResult, err
	}
	req.Header.Add("Accept", "application/json")
	req.Header.Add("User-Agent", "PersonalLibraryManager/0.1 (artlef@protonmail.com)")
	resp, err := client.Do(req)
	if err != nil {
		return queryResult, err
	}
	defer resp.Body.Close()

	bodyBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		return queryResult, err
	}
	bodyString := string(bodyBytes)
	decoder := json.NewDecoder(strings.NewReader(bodyString))
	err = decoder.Decode(&queryResult)
	return queryResult, err
}

func addQueryParamInt(u *url.URL, paramName string, paramValue int) {
	addQueryParam(u, paramName, strconv.Itoa(paramValue))
}

func addQueryParam(u *url.URL, paramName string, paramValue string) {
	q := u.Query()
	q.Set(paramName, paramValue)
	u.RawQuery = q.Encode()
}